Would be scary if not for the fact that . . . the Sun itself will have bloated into a Red Giant and puffed up so that its outer layers envelope Mercury and (if memory serves) even Venus. If memory serves this will occur within about 6 billion years? (might only be 3 . . .). However, all life on Earth will have been exterminated by the "dying" sun long before that. I want to say that within 2 to 2.5 billion years, the progression of the Sun into its next life stage will have increased its size and energetic output to the point that liquid water will become impossible on Earth.

Not to mention the fact that, Milky Way and Andromeda will have collide sometime around the 3 billion year mark? That may in fact not have much negative impact on the Sol solar system, but I think they are not entirely certain. Tossing two galaxies at each other in the cosmic blender strikes me as posing a bit of risk to virtually any object in those galaxies!

The Solar System is chaotic over million- and billion-year timescales,[88] with the orbits of the planets open to long-term variations. One notable example of this chaos is the Neptune–Pluto system, which lies in a 3:2 orbital resonance. Although the resonance itself will remain stable, it becomes impossible to predict the position of Pluto with any degree of accuracy more than 10–20 million years (the Lyapunov time) into the future.[89] Another example is Earth's axial tilt, which, due to friction raised within Earth's mantle by tidal interactions with the Moon (see below), will be incomputable at some point between 1.5 and 4.5 billion years from now.[90]The outer planets' orbits are chaotic over longer timescales, with a Lyapunov time in the range of 2–230 million years.[91] In all cases this means that the position of a planet along its orbit ultimately becomes impossible to predict with any certainty (so, for example, the timing of winter and summer become uncertain), but in some cases the orbits themselves may change dramatically. Such chaos manifests most strongly as changes in eccentricity, with some planets' orbits becoming significantly more—or less—elliptical.[92]Ultimately, the Solar System is stable in that none of the planets are likely to collide with each other or be ejected from the system in the next few billion years.[91] Beyond this, within five billion years or so Mars's eccentricity may grow to around 0.2, such that it lies on an Earth-crossing orbit, leading to a potential collision. In the same timescale, Mercury's eccentricity may grow even further, and a close encounter with Venus could theoretically eject it from the Solar System altogether[88] or send it on a collision course with Venus or Earth.[93] This could happen within a billion years, according to numerical simulations in which Mercury's orbit is perturbed.[94]

Ah and here is the accurate detail about the "death" of the sun . . .

Quote:

In the long term, the greatest changes in the Solar System will come from changes in the Sun itself as it ages. As the Sun burns through its supply of hydrogen fuel, it gets hotter and burns the remaining fuel even faster. As a result, the Sun is growing brighter at a rate of ten percent every 1.1 billion years.[106] In one billion years' time, as the Sun's radiation output increases, its circumstellar habitable zone will move outwards, making the Earth's surface too hot for liquid water to exist there naturally. At this point, all life on land will become extinct.[107] Evaporation of water, a potent greenhouse gas, from the oceans' surface could accelerate temperature increase, potentially ending all life on Earth even sooner.[108] During this time, it is possible that as Mars's surface temperature gradually rises, carbon dioxide and water currently frozen under the surface regolith will release into the atmosphere, creating a greenhouse effect that will heat the planet until it achieves conditions parallel to Earth today, providing a potential future abode for life.[109] By 3.5 billion years from now, Earth's surface conditions will be similar to those of Venus today.[106]

Holy shit! My memory was off by a lot!

Only 1.1 billion years of habitable Earth left

Some more interesting factoids . . .

Quote:

Around 5.4 billion years from now, the core of the Sun will become hot enough to trigger hydrogen fusion in its surrounding shell.[107] This will cause the outer layers of the star to expand greatly, and the star will enter a phase of its life in which it is called a red giant.[110][111] Within 7.5 billion years, the Sun will have expanded to a radius of 1.2 AU—256 times its current size. At the tip of the red giant branch, as a result of the vastly increased surface area, the Sun's surface will be much cooler (about 2600 K) than now and its luminosity much higher—up to 2,700 current solar luminosities. For part of its red giant life, the Sun will have a strong stellar wind that will carry away around 33% of its mass.[107][112][113] During these times, it is possible that Saturn's moon Titan could achieve surface temperatures necessary to support life.[114][115]As the Sun expands, it will swallow the planets Mercury and Venus.[116] Earth's fate is less clear; although the Sun will envelop Earth's current orbit, the star's loss of mass (and thus weaker gravity) will cause the planets' orbits to move farther out.[107] If it were only for this, Venus and Earth would probably escape incineration,[112] but a 2008 study suggests that Earth will likely be swallowed up as a result of tidal interactions with the Sun's weakly bound outer envelope.[107]

Gradually, the hydrogen burning in the shell around the solar core will increase the mass of the core until it reaches about 45% of the present solar mass. At this point the density and temperature will become so high that the fusion of helium into carbon will begin, leading to a helium flash; the Sun will shrink from around 250 to 11 times its present (main-sequence) radius. Consequently, its luminosity will decrease from around 3,000 to 54 times its current level, and its surface temperature will increase to about 4770 K. The Sun will become a horizontal giant, burning helium in its core in a stable fashion much like it burns hydrogen today. The helium-fusing stage will last only 100 million years. Eventually, it will have to again resort to the reserves of hydrogen and helium in its outer layers and will expand a second time, turning into what is known as an asymptotic giant. Here the luminosity of the Sun will increase again, reaching about 2,090 present luminosities, and it will cool to about 3500 K.[107] This phase lasts about 30 million years, after which, over the course of a further 100,000 years, the Sun's remaining outer layers will fall away, ejecting a vast stream of matter into space and forming a halo known (misleadingly) as a planetary nebula. The ejected material will contain the helium and carbon produced by the Sun's nuclear reactions, continuing the enrichment of the interstellar medium with heavy elements for future generations of stars.[117]

_________________Nero: So what is your challenge?

Anthro: Answer question #2: How do "Climate Change models" mathematically control for the natural forces which caused the Ice Age(s) to come and go . . . repeatedly?

When the sun does the red giant thing the particle density at earth's orbit won't be enough to muck with the relative position of the earth and the moon. It'll be something like 1 gram per million cubic meters.

The bad news is what happens long before that. The sun's luminosity increases about 1% per 100 million years. So in two or three billion years, runaway greenhouse effect will destroy all life on earth. The good news is that the "habitable zone" around the sun will expand outward accordingly. So if one is inclined to live in the belt, solar power will be an outstanding and cheap source of energy, and living out by Jupiter or Saturn will be less unpleasant.

Many dads tinker in the backyard shed. William Atteridge of Natchitoches, La. was building masterpieces. His family didn’t realize it.

“My mom wasn’t all that thrilled with Dad spending a lot of time in the shop,” says Larry Atteridge, William’s son. “As a young man, I didn’t pay as much attention to what he was doing. When you’re 16 or 17 years old, the last thing you’re worrying about is your dad building models.”

But since his father died, Larry Atteridge learned a lot about the miniature fleet he inherited. It turns out his dad made more than a thousand replicas of Civil War ships with incredible precision that garnered a worldwide following among Civil War enthusiasts.

Many dads tinker in the backyard shed. William Atteridge of Natchitoches, La. was building masterpieces. His family didn’t realize it.

“My mom wasn’t all that thrilled with Dad spending a lot of time in the shop,” says Larry Atteridge, William’s son. “As a young man, I didn’t pay as much attention to what he was doing. When you’re 16 or 17 years old, the last thing you’re worrying about is your dad building models.”

But since his father died, Larry Atteridge learned a lot about the miniature fleet he inherited. It turns out his dad made more than a thousand replicas of Civil War ships with incredible precision that garnered a worldwide following among Civil War enthusiasts.

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